lisp/mail/uudecode.el

   1 ;;; uudecode.el -- elisp native uudecode
   2
   3 ;; Copyright (C) 1998-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
   6 ;; Keywords: uudecode news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28
  29 (eval-and-compile
  30   (defalias 'uudecode-char-int
  31     (if (fboundp 'char-int)
  32         'char-int
  33       'identity)))
  34
  35 (defgroup uudecode nil
  36   "Decoding of uuencoded data."
  37   :group 'mail
  38   :group 'news)
  39
  40 (defcustom uudecode-decoder-program "uudecode"
  41   "Non-nil value should be a string that names a uu decoder.
  42 The program should expect to read uu data on its standard
  43 input and write the converted data to its standard output."
  44   :type 'string
  45   :group 'uudecode)
  46
  47 (defcustom uudecode-decoder-switches nil
  48   "List of command line flags passed to `uudecode-decoder-program'."
  49   :group 'uudecode
  50   :type '(repeat string))
  51
  52 (defcustom uudecode-use-external
  53   (executable-find uudecode-decoder-program)
  54   "Use external uudecode program."
  55   :version "22.1"
  56   :group 'uudecode
  57   :type 'boolean)
  58
  59 (defconst uudecode-alphabet "\040-\140")
  60
  61 (defconst uudecode-begin-line "^begin[ \t]+[0-7][0-7][0-7][ \t]+\\(.*\\)$")
  62 (defconst uudecode-end-line "^end[ \t]*$")
  63
  64 (defconst uudecode-body-line
  65   (let ((i 61) (str "^M"))
  66     (while (> (setq i (1- i)) 0)
  67       (setq str (concat str "[^a-z]")))
  68     (concat str ".?$")))
  69
  70 (defvar uudecode-temporary-file-directory
  71   (cond ((fboundp 'temp-directory) (temp-directory))
  72         ((boundp 'temporary-file-directory) temporary-file-directory)
  73         ("/tmp")))
  74
  75 ;;;###autoload
  76 (defun uudecode-decode-region-external (start end &optional file-name)
  77   "Uudecode region between START and END using external program.
  78 If FILE-NAME is non-nil, save the result to FILE-NAME.  The program
  79 used is specified by `uudecode-decoder-program'."
  80   (interactive "r\nP")
  81   (let ((cbuf (current-buffer)) tempfile firstline status)
  82     (save-excursion
  83       (goto-char start)
  84       (when (re-search-forward uudecode-begin-line nil t)
  85         (forward-line 1)
  86         (setq firstline (point))
  87         (cond ((null file-name))
  88               ((stringp file-name))
  89               (t
  90                (setq file-name (read-file-name "File to Name:"
  91                                                nil nil nil
  92                                                (match-string 1)))))
  93         (setq tempfile (if file-name
  94                            (expand-file-name file-name)
  95                            (if (fboundp 'make-temp-file)
  96                                (let ((temporary-file-directory
  97                                       uudecode-temporary-file-directory))
  98                                  (make-temp-file "uu"))
  99                              (expand-file-name
 100                               (make-temp-name "uu")
 101                               uudecode-temporary-file-directory))))
 102         (let ((cdir default-directory)
 103               (default-process-coding-system
 104                 (if (featurep 'xemacs)
 105                     ;; In XEmacs, nil is not a valid coding system.
 106                     '(binary . binary)
 107                   nil)))
 108           (unwind-protect
 109               (with-temp-buffer
 110                 (insert "begin 600 " (file-name-nondirectory tempfile) "\n")
 111                 (insert-buffer-substring cbuf firstline end)
 112                 (cd (file-name-directory tempfile))
 113                 (apply 'call-process-region
 114                        (point-min)
 115                        (point-max)
 116                        uudecode-decoder-program
 117                        nil
 118                        nil
 119                        nil
 120                        uudecode-decoder-switches))
 121             (cd cdir) (set-buffer cbuf)))
 122         (if (file-exists-p tempfile)
 123             (unless file-name
 124               (goto-char start)
 125               (delete-region start end)
 126               (let (format-alist)
 127                 (insert-file-contents-literally tempfile)))
 128           (message "Can not uudecode")))
 129       (ignore-errors (or file-name (delete-file tempfile))))))
 130
 131 (eval-and-compile
 132   (defalias 'uudecode-string-to-multibyte
 133     (cond
 134      ((featurep 'xemacs)
 135       'identity)
 136      ((fboundp 'string-to-multibyte)
 137       'string-to-multibyte)
 138      (t
 139       (lambda (string)
 140         "Return a multibyte string with the same individual chars as string."
 141         (mapconcat
 142          (lambda (ch) (string-as-multibyte (char-to-string ch)))
 143          string ""))))))
 144
 145 ;;;###autoload
 146 (defun uudecode-decode-region-internal (start end &optional file-name)
 147   "Uudecode region between START and END without using an external program.
 148 If FILE-NAME is non-nil, save the result to FILE-NAME."
 149   (interactive "r\nP")
 150   (let ((done nil)
 151         (counter 0)
 152         (remain 0)
 153         (bits 0)
 154         (lim 0) inputpos result
 155         (non-data-chars (concat "^" uudecode-alphabet)))
 156     (save-excursion
 157       (goto-char start)
 158       (when (re-search-forward uudecode-begin-line nil t)
 159         (cond ((null file-name))
 160               ((stringp file-name))
 161               (t
 162                (setq file-name (expand-file-name
 163                                 (read-file-name "File to Name:"
 164                                                 nil nil nil
 165                                                 (match-string 1))))))
 166         (forward-line 1)
 167         (skip-chars-forward non-data-chars end)
 168         (while (not done)
 169           (setq inputpos (point))
 170           (setq remain 0 bits 0 counter 0)
 171           (cond
 172            ((> (skip-chars-forward uudecode-alphabet end) 0)
 173             (setq lim (point))
 174             (setq remain
 175                   (logand (- (uudecode-char-int (char-after inputpos)) 32)
 176                           63))
 177             (setq inputpos (1+ inputpos))
 178             (if (= remain 0) (setq done t))
 179             (while (and (< inputpos lim) (> remain 0))
 180               (setq bits (+ bits
 181                             (logand
 182                              (-
 183                               (uudecode-char-int (char-after inputpos)) 32)
 184                              63)))
 185               (if (/= counter 0) (setq remain (1- remain)))
 186               (setq counter (1+ counter)
 187                     inputpos (1+ inputpos))
 188               (cond ((= counter 4)
 189                      (setq result (cons
 190                                    (concat
 191                                     (char-to-string (lsh bits -16))
 192                                     (char-to-string (logand (lsh bits -8) 255))
 193                                     (char-to-string (logand bits 255)))
 194                                    result))
 195                      (setq bits 0 counter 0))
 196                     (t (setq bits (lsh bits 6)))))))
 197           (cond
 198            (done)
 199            ((> 0 remain)
 200             (error "uucode line ends unexpectedly")
 201             (setq done t))
 202            ((and (= (point) end) (not done))
 203             ;;(error "uucode ends unexpectedly")
 204             (setq done t))
 205            ((= counter 3)
 206             (setq result (cons
 207                           (concat
 208                            (char-to-string (logand (lsh bits -16) 255))
 209                            (char-to-string (logand (lsh bits -8) 255)))
 210                           result)))
 211            ((= counter 2)
 212             (setq result (cons
 213                           (char-to-string (logand (lsh bits -10) 255))
 214                           result))))
 215           (skip-chars-forward non-data-chars end))
 216         (if file-name
 217             (with-temp-file file-name
 218               (unless (featurep 'xemacs) (set-buffer-multibyte nil))
 219               (insert (apply 'concat (nreverse result))))
 220           (or (markerp end) (setq end (set-marker (make-marker) end)))
 221           (goto-char start)
 222           (if enable-multibyte-characters
 223               (dolist (x (nreverse result))
 224                 (insert (uudecode-string-to-multibyte x)))
 225             (insert (apply 'concat (nreverse result))))
 226           (delete-region (point) end))))))
 227
 228 ;;;###autoload
 229 (defun uudecode-decode-region (start end &optional file-name)
 230   "Uudecode region between START and END.
 231 If FILE-NAME is non-nil, save the result to FILE-NAME."
 232   (if uudecode-use-external
 233       (uudecode-decode-region-external start end file-name)
 234     (uudecode-decode-region-internal start end file-name)))
 235
 236 (provide 'uudecode)
 237
 238 ;;; uudecode.el ends here